The fan is similar to a muffin fan on a desk top computer. Mine is audible when on, usually a thermostat in the convertor controls it to reduce heat when under a load.
Sounds like a possibility. Make sure you are using some dc voltage( under load) when testing as it may not come on under normal conditions.
2011 351RLTS Eagle, Mor/Ryde suspension & pin box
06 F350 Lariat PSD, SRW, LB, CC, EGR delete kit, 16K DrawTite hitch, Timbrens, TST TPMS
Can't find what you're looking on JOF? Try:Jayco Owners Forum Custom Google Search
"It's easier to fool people than to convince them that they have been fooled." - Mark Twain